There has been a demand for a finer pattern in an exposure process by a semiconductor device as circuit density and circuit speed are increased. As a main technique to achieve a finer pattern, decreasing the wavelength of an exposure source has been desired. For example, a technique using extreme ultraviolet light (EUV, wavelength: 13.5 nm) has undergone much development as being promising in production of next-generation semiconductor devices. However, it is difficult to develop a light source device with a high power (100 W) needed to apply the device to mass production; devices that have been developed so far have a power not more than 10 W and take time to complete exposure for forming a latent pattern image. Meanwhile, an electron beam direct writing method uses an electron beam (EB) having a small beam diameter and therefore allows formation of a fine pattern with high dimensional precision but takes more time to write a more complicated and larger-area pattern. As described above, the problem with the exposure techniques using extreme ultraviolet light or an electron beam is that the throughput is low while a fine pattern can be formed.
To solve the problem, improvement in the sensitivity of resist materials is being promoted with an aim to reduce exposure time as much as possible. For example, a resist composition disclosed in Patent Literature 1 is composed of a specified resin and a specified compound, and thus improved in sensitivity and resolution.